Sugar-Sweetened Beverage Consumption and Cardiometabolic Risk Factors

Background: Currently, sugar-sweetened beverages (SSB) account for 6% and 9% of energy intake in American adults and children, respectively. Recently, much attention has focused on the potential, detrimental public health impact of SSB consumption on cardiometabolic diseases. Many observational studies have examined the associations between habitual SSB intake and cardiometabolic risk factors; however, little evidence exists examining the role of habitual SSB intake on ectopic fat accumulation and insulin resistance.;Aims: The objective of this dissertation is to examine the associations between habitual SSB intake and 1) fat accumulation in abdominal visceral adipose and subcutaneous depots, 2) risk of fatty liver disease, and 3) progression of insulin resistance and risk of pre-diabetes.;Methods: Data from the Framingham Offspring cohort and Third Generation cohorts were examined. Habitual intake of SSB and diet soda was assessed by a validated food frequency questionnaire. Ectopic fat accumulation in visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and liver were measured using computed tomography. Fatty liver disease was defined using measures of liver fat content. Insulin resistance was assessed using homeostatic model assessment insulin resistance (HOMA-IR). Aim 1: Least-squares means of VAT, SAT, and VAT:SAT ratio across SSB and diet soda categories were calculated in a cross-sectional analysis of 2,596 middle-aged participants. Aim 2: Odds ratios of fatty liver disease in SSB and diet soda consumers relative to non-consumers were estimated in a separate cross-sectional analysis of 2,634 participants. Aim 3: Least-squares means of progression of HOMA-IR (n=2,092 participants) and relative risk of incident pre-diabetes and diabetes (n=1,981 participants) were calculated in a prospective analysis utilizing over 7 years of data.;Results: Aim 1: SSB consumption was significantly associated with a greater VAT (P-trend<0.001) and a reduced SAT (P-trend<0.001). SSB intake was also positively associated with an increased VAT:SAT ratio (P-trend<0.001). Daily SSB consumers had a 10% higher absolute VAT volume, 12% lower absolute SAT volume, and a 15% greater VAT:SAT ratio compared to SSB non-consumers. Aim 2: After adjustment for multiple confounders including BMI, SSB consumption was associated with increased risk of fatty liver disease (P-trend=0.02), with a 55% increased risk of fatty liver disease in daily consumers of SSB compared to non-consumers. SSB consumers tended to have a greater liver fat content, however, this association was only significant in overweight and obese participants (P-trend=0.03). SSB intake was also positively associated with ALT levels (P-trend=0.007), a surrogate marker of fatty liver disease. Aim 3: SSB intake was positively associated with change in HOMA-IR (P-trend=0.04). SSB intake was associated with a higher incident risk of pre-diabetes (P-trend=0.03), with those in the highest category of consumption (>3 servings/week, median 6 servings/week) having a 39% increased incidence of pre-diabetes compared with non-consumers. Diet soda intake was not associated with abdominal ectopic fat accumulation (VAT or VAT:SAT ratio), risk of fatty liver disease, or progression of insulin resistance.;Summary and Conclusion: Collectively, our observations contribute to the existing literature showing that, independent of body weight, habitual SSB intake is associated with an increased fat partitioning to VAT, greater prevalence of fatty liver disease, and elevated insulin resistance. Given that SSB are a major source of added sugars in the American diet, these results support the hypothesis that excessive habitual intake of SSB is associated with greater cardiometabolic risk.